(*  Title: 	Provers/clasimp.ML

    ID:         $Id$

    Author:     David von Oheimb, TU Muenchen

Combination of classical reasoner and simplifier (depends on

simplifier.ML, splitter.ML classical.ML, blast.ML).

*)

infix 4 addSIs2 addSEs2 addSDs2 addIs2 addEs2 addDs2 addsimps2 delsimps2;

infix 4 addSss addss;

signature CLASIMP_DATA =

sig

  structure Simplifier: SIMPLIFIER

  structure Splitter: SPLITTER

  structure Classical: CLASSICAL

  structure Blast: BLAST

  sharing type Classical.claset = Blast.claset

end

signature CLASIMP =

sig

  include CLASIMP_DATA

  type claset

  type simpset

  type clasimpset

  val addSIs2	: clasimpset * thm list -> clasimpset

  val addSEs2	: clasimpset * thm list -> clasimpset

  val addSDs2	: clasimpset * thm list -> clasimpset

  val addIs2	: clasimpset * thm list -> clasimpset

  val addEs2	: clasimpset * thm list -> clasimpset

  val addDs2	: clasimpset * thm list -> clasimpset

  val addsimps2	: clasimpset * thm list -> clasimpset

  val delsimps2	: clasimpset * thm list -> clasimpset

  val addSss	: claset * simpset -> claset

  val addss	: claset * simpset -> claset

  val CLASIMPSET  :(clasimpset -> tactic) -> tactic

  val CLASIMPSET' :(clasimpset -> 'a -> tactic) -> 'a -> tactic

  val clarsimp_tac: clasimpset -> int -> tactic

  val Clarsimp_tac:               int -> tactic

  val mk_auto_tac : clasimpset -> int -> int -> tactic

  val auto_tac	  : clasimpset -> tactic

  val Auto_tac	  : tactic

  val auto	  : unit -> unit

  val force_tac	  : clasimpset  -> int -> tactic

  val Force_tac	  : int -> tactic

  val force	  : int -> unit

  val change_global_css: (clasimpset * thm list -> clasimpset) -> theory attribute

  val change_local_css: (clasimpset * thm list -> clasimpset) -> Proof.context attribute

  val get_local_clasimpset: Proof.context -> clasimpset

  val clasimp_modifiers: (Args.T list -> (Method.modifier * Args.T list)) list

  val setup	  : (theory -> theory) list

end;

functor ClasimpFun(Data: CLASIMP_DATA): CLASIMP =

struct

open Data;

type claset = Classical.claset;

type simpset = Simplifier.simpset;

type clasimpset = claset * simpset;

(* clasimpset operations *)

(*this interface for updating a clasimpset is rudimentary and just for

  convenience for the most common cases*)

fun pair_upd1 f ((a,b),x) = (f(a,x), b);

fun pair_upd2 f ((a,b),x) = (a, f(b,x));

fun op addSIs2   arg = pair_upd1 Classical.addSIs arg;

fun op addSEs2   arg = pair_upd1 Classical.addSEs arg;

fun op addSDs2   arg = pair_upd1 Classical.addSDs arg;

fun op addIs2    arg = pair_upd1 Classical.addIs arg;

fun op addEs2    arg = pair_upd1 Classical.addEs arg;

fun op addDs2    arg = pair_upd1 Classical.addDs arg;

fun op addsimps2 arg = pair_upd2 Simplifier.addsimps arg;

fun op delsimps2 arg = pair_upd2 Simplifier.delsimps arg;

(*not totally safe: may instantiate unknowns that appear also in other subgoals*)

val safe_asm_full_simp_tac = Simplifier.generic_simp_tac true (true,true,true);

(*Add a simpset to a classical set!*)

(*Caution: only one simpset added can be added by each of addSss and addss*)

fun cs addSss ss = Classical.addSaltern (cs, ("safe_asm_full_simp_tac",

			    CHANGED o safe_asm_full_simp_tac ss));

fun cs addss  ss = Classical.addbefore  (cs, ("asm_full_simp_tac", 

			    CHANGED o Simplifier.asm_full_simp_tac ss));

(* tacticals *)

fun CLASIMPSET tacf state =

  Classical.CLASET (fn cs => Simplifier.SIMPSET (fn ss => tacf (cs, ss))) state;

fun CLASIMPSET' tacf i state =

  Classical.CLASET (fn cs => Simplifier.SIMPSET (fn ss => tacf (cs, ss) i)) state;

fun clarsimp_tac (cs, ss) = safe_asm_full_simp_tac ss THEN_ALL_NEW

			    Classical.clarify_tac (cs addSss ss);

fun Clarsimp_tac i = clarsimp_tac (Classical.claset(), Simplifier.simpset()) i;

(* auto_tac *)

fun blast_depth_tac cs m i thm =

    Blast.depth_tac cs m i thm 

      handle Blast.TRANS s => (warning ("Blast_tac: " ^ s); Seq.empty);

(* a variant of depth_tac that avoids interference of the simplifier 

   with dup_step_tac when they are combined by auto_tac *)

local

fun slow_step_tac' cs = Classical.appWrappers cs 

	(Classical.instp_step_tac cs APPEND' Classical.haz_step_tac cs);

in fun nodup_depth_tac cs m i state = SELECT_GOAL 

   (Classical.safe_steps_tac cs 1 THEN_ELSE 

	(DEPTH_SOLVE (nodup_depth_tac cs m 1),

	 Classical.inst0_step_tac cs 1 APPEND COND (K (m=0)) no_tac

	     (slow_step_tac' cs 1 THEN DEPTH_SOLVE (nodup_depth_tac cs (m-1) 1))

        )) i state;

end;

(*Designed to be idempotent, except if blast_depth_tac instantiates variables

  in some of the subgoals*)

fun mk_auto_tac (cs, ss) m n =

    let val cs' = cs addss ss

        val maintac = 

          blast_depth_tac cs m		     (* fast but can't use wrappers *)

          ORELSE'

          (CHANGED o nodup_depth_tac cs' n); (* slower but more general *)

    in  EVERY [ALLGOALS (Simplifier.asm_full_simp_tac ss),

	       TRY (Classical.safe_tac cs),

	       REPEAT (FIRSTGOAL maintac),

               TRY (Classical.safe_tac (cs addSss ss)),

	       prune_params_tac] 

    end;

fun auto_tac (cs,ss) = mk_auto_tac (cs,ss) 4 2;

fun Auto_tac st = auto_tac (Classical.claset(), Simplifier.simpset()) st;

fun auto () = by Auto_tac;

(* force_tac *)

(* aimed to solve the given subgoal totally, using whatever tools possible *)

fun force_tac (cs,ss) = let val cs' = cs addss ss in SELECT_GOAL (EVERY [

	Classical.clarify_tac cs' 1,

	IF_UNSOLVED (Simplifier.asm_full_simp_tac ss 1),

	ALLGOALS (Classical.first_best_tac cs')]) end;

fun Force_tac i = force_tac (Classical.claset(), Simplifier.simpset()) i;

fun force i = by (Force_tac i);

(* attributes *)

fun change_global_css f (thy, th) =

  let

    val cs_ref = Classical.claset_ref_of thy;

    val ss_ref = Simplifier.simpset_ref_of thy;

    val (cs', ss') = f ((! cs_ref, ! ss_ref), [th]);

  in cs_ref := cs'; ss_ref := ss'; (thy, th) end;

fun change_local_css f (ctxt, th) =

  let

    val cs = Classical.get_local_claset ctxt;

    val ss = Simplifier.get_local_simpset ctxt;

    val (cs', ss') = f ((cs, ss), [th]);

    val ctxt' =

      ctxt

      |> Classical.put_local_claset cs'

      |> Simplifier.put_local_simpset ss';

  in (ctxt', th) end;

(* methods *)

fun get_local_clasimpset ctxt =

  (Classical.get_local_claset ctxt, Simplifier.get_local_simpset ctxt);

val clasimp_modifiers =

  Simplifier.simp_modifiers @ Splitter.split_modifiers @ Classical.cla_modifiers;

fun clasimp_meth tac prems ctxt = Method.METHOD (fn facts =>

  ALLGOALS (Method.insert_tac (prems @ facts)) THEN tac (get_local_clasimpset ctxt));

fun clasimp_meth' tac prems ctxt = Method.METHOD (fn facts =>

  HEADGOAL (Method.insert_tac (prems @ facts) THEN' tac (get_local_clasimpset ctxt)));

val clasimp_method = Method.bang_sectioned_args clasimp_modifiers o clasimp_meth;

val clasimp_method' = Method.bang_sectioned_args clasimp_modifiers o clasimp_meth';

val setup =

 [Method.add_methods

   [("force", clasimp_method' force_tac, "force"),

    ("auto", clasimp_method (CHANGED o auto_tac), "auto"),

    ("clarsimp", clasimp_method' clarsimp_tac, "clarify simplified goal")]];

end;